sebix

Icinga on Lighttpd and Wheezy

Thu, 02 Jan 2014 15:46:00 GMT

As I haven’t found any working example configuration for running icinga on a sub domain with lighttpd, I will here present my working solution.
First of all, we need to install the software itself:

          $ apt-get install icinga icinga-doc

We create the file /etc/lighttpd/conf-available/50-icinga.conf to have a configuration which is easy en- and disable:



        $HTTP[“host”] =~ “icinga.example.org” {
        	auth.backend = “htdigest”
        	auth.backend.htdigest.userfile = “/etc/lighttpd/icinga.htdigest”
        	auth.require = ( “/” => (
        		“method”  => “digest”,
        		“realm”   => “icinga”,
        		“require” => “valid-user” 
        		) )
        
        	server.document-root = “/usr/share/icinga/htdocs”
        	alias.url += (
        		“/cgi-bin/icinga” => “/usr/lib/cgi-bin/icinga”,
        		“/icinga/stylesheets” => “/etc/icinga/stylesheets/”,
        		“/icinga” => “/usr/share/icinga/htdocs”,
        		“/stylesheets” => “/etc/icinga/stylesheets/”,
        	)
        
        	$HTTP[“url”] =~ “^/cgi-bin/” {
        		dir-listing.activate = “disable” 
        		cgi.assign = (
        			“.pl”  => “/usr/bin/perl”,
        			“.cgi” => “” 
        		)
        	}
        }

Now we can activate the newly created config and two requirements for Lighty’s config using:

          $ lighty-enable-mod auth cgi icinga

The authentication is required by icinga and it is highly encouraged not to use a common password and a common sub domain. If the web interface does not detect any user name, it will load the website, but the access to the data is restricted to valid users.

Now we need to create the digest file, containing the user names and password-hashes. We can therefor use the program htdigest, provided by apache2-utils, which should have been installed as a dependency of icinga.

          $ htdigest -c "/etc/lighttpd/icinga.htdigest" icinga icingaadmin

For Icinga on Lighttpd using a sub directory, take a look at Cyconet Blog: Running Icinga With Lighttpd on Debian Wheezy

Automatic hyphenation

Sun, 15 Apr 2012 15:46:00 GMT

Reasons for full justification

Some weeks ago I began to play around with full justification of texts beyond LaTeX. Fully justified texts are used by professional typesetters and they can be found in almost every newspaper. Full justification is necessary there, because otherwise the reader would loose the orientation between all the small columns. They also appear more and more in the Internet as it just looks more professional and is far easier to read, in particular when the paragraph widths are small. This is the case on mobile devices and in multi-column-layouts using HTML5.

Responsive Design

There’s an important link to Responsive Webdesign as the justification depends essentially on the display-width. If a fully justified paragraph is hyphened with the usual hyphen -, it works only for a specific text/box-width and usually fails with slightly changed rendering conditions. Not only in Responsive Design, it is expected that all texts are scaling properly and are displayed in a readable and consistent fashion, so a “hard hyphen” - is a very bad idea.

Some time ago a found a website of a professional marketing group which had a short (fully justified) paragraph at the top of their homepage. But they used just a normal hyphen -, which results in ugly white spaces between the words when zooming in/out. This is of course not a good way to create justified paragraphs and can result in a bad impression!

Typography

Above I mentioned already TeX, which has a great (maybe the best?) hyphenation algorithm. Anyway, it’s the best open one ;-). This algorithm uses syllable division based on language-specific patterns. Of course there exist many exceptions to this common rules, but the TeX-algorithm is very well-engineered and fails very rarely under special and unpredictable cases (in these cases you can help TeX by adding your own rules).

A simple hyphenation algorithm with pattern-detection can be easily implemented, but I only want perfect solutions. So, professional setting programs have their (good) solutions and take their time to process all the data. So what are the solutions for the web?

Solutions for the Web

The problem is that most Browser don’t have syllable division algorithms implemented, so the developers and web designers have to take care about this issue. There exist several solutions which enable automatic hyphenation on the web. Some are implemented in JavaScript, which generate the hyphenation at run-/render-time in the browser. In my opinion this is the worst idea to solve this problem, as JavaScript is required and the hyphenation is done for every rendering and every client (resulting in longer rendering times), thus it is more inefficient than other solutions.

Others generate the so-called “soft-hyphens” at run- or compile-time (on the server by a CGI-language or locally by static compilers), which are embedded in the HTML-sourcecode by the -code. These HTML-Codes are hints for the browser and signal them the possible syllable divisions. The Browser then knows where an in-word break is possible and justifies the paragraph perfectly depending on the block width. This method is used by acrylamid via a filter and therefore also enabled on this homepage. It is the best method for the time being, because it is supported by all browsers! The only downside of the soft hyphens is, that the text is quite unreadable in the source code (semantic expressions are of course not affected).

CSS3

The best news is an upcoming feature of CSS3, called hyphens. It enables automatic hyphenation algorithms in the browsers, so that they can finally do the work they have to do: display content properly. The feature is yet not fully implemented in every browser, so that browser-specific properties have to be used. Additionally the browsers may not support all languages yet.

body {
          -moz-hyphens: auto;
          -ms-hyphens: auto;
          -o-hyphens: auto;
          -webkit-hyphens: auto;
          hyphens: auto;
        }

At the time being, the feature is not at all reliably implemented! The best way remains adding soft hyphens until every browser has a good hyphenation algorithm. Nevertheless I added this code to my stylesheet, maybe it is helpful for some renderings.

The current state of art can be tested on a private test-page. The specification is – as usual – at W3.org in the section CSS Text Level 3.

The Particle Zoo of Modern Physics

Sat, 14 Apr 2012 11:53:00 GMT

Get it!

Click on image above or choose:

Download current PDF
Download current PNG (low quality!)
View current SVG
View Github-Project

The overview has gone… and reappears!

When beginning to focus my interest on modern physics as well as preparing for my thesis in physics for school I always lost the overview due to the huge mass of information. Furthermore I was unable to find any good reference sheet or an overview about all the particles of the standard-model of modern physics. So I decided in my distress to create my own one, therefore I would have to study the subject matter very deep and additionally it could help others.

The target of this cheatsheet

My cheatsheet is meant to help upcoming and learning interested parties to ease their start in modern particle physics. The Cheatsheet is neither complete nor mathematically correct, what it is not meant to become! The particle zoo is intended for a kick start, not as scientific reference.

The shown data

I included only the data I was interested in, especially basic properties like spin, mass, electric charge, lifetime and eventual sub particles. Structuring the individual particles in their typical groups, helped me a lot in understanding all the special relationships.

Enhance it!

The Particle Zoo has been published under the Creative-Commons License, permitting distribution and editing. I also appreciate any feedback to make it just perfect ;)

sebix

Icinga on Lighttpd and Wheezy

Automatic hyphenation

Rea­sons for full jus­ti­fi­ca­tion

Re­spon­sive De­sign

Ty­pog­ra­phy

So­lu­tions for the Web